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authorPeter Ujfalusi <peter.ujfalusi@ti.com>2015-10-30 09:00:36 +0100
committerVinod Koul <vinod.koul@intel.com>2015-11-30 10:39:16 +0100
commitec9bfa1e1a796ef7acc2e55917c9b8be5a79e70e (patch)
treedba51fd383cbb59464975b2acb3b60f532881a97 /drivers/dma/ti-dma-crossbar.c
parentdmaengine: ti-dma-crossbar: dra7: Support for eDMA with new bindings (diff)
downloadlinux-ec9bfa1e1a796ef7acc2e55917c9b8be5a79e70e.tar.xz
linux-ec9bfa1e1a796ef7acc2e55917c9b8be5a79e70e.zip
dmaengine: ti-dma-crossbar: dra7: Use bitops instead of idr
The use of idr was nice, but it was a bit heavy and we did not need the features it provides. Using simple bitmap to track allocated DMA channels is adequate here and it will be easier to add support for reserving channels later on. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma/ti-dma-crossbar.c')
-rw-r--r--drivers/dma/ti-dma-crossbar.c30
1 files changed, 23 insertions, 7 deletions
diff --git a/drivers/dma/ti-dma-crossbar.c b/drivers/dma/ti-dma-crossbar.c
index fccf65f89075..7b1e3ea874bf 100644
--- a/drivers/dma/ti-dma-crossbar.c
+++ b/drivers/dma/ti-dma-crossbar.c
@@ -12,7 +12,6 @@
#include <linux/init.h>
#include <linux/list.h>
#include <linux/io.h>
-#include <linux/idr.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/of_dma.h>
@@ -198,7 +197,8 @@ struct ti_dra7_xbar_data {
void __iomem *iomem;
struct dma_router dmarouter;
- struct idr map_idr;
+ struct mutex mutex;
+ unsigned long *dma_inuse;
u16 safe_val; /* Value to rest the crossbar lines */
u32 xbar_requests; /* number of DMA requests connected to XBAR */
@@ -225,7 +225,9 @@ static void ti_dra7_xbar_free(struct device *dev, void *route_data)
map->xbar_in, map->xbar_out);
ti_dra7_xbar_write(xbar->iomem, map->xbar_out, xbar->safe_val);
- idr_remove(&xbar->map_idr, map->xbar_out);
+ mutex_lock(&xbar->mutex);
+ clear_bit(map->xbar_out, xbar->dma_inuse);
+ mutex_unlock(&xbar->mutex);
kfree(map);
}
@@ -255,8 +257,17 @@ static void *ti_dra7_xbar_route_allocate(struct of_phandle_args *dma_spec,
return ERR_PTR(-ENOMEM);
}
- map->xbar_out = idr_alloc(&xbar->map_idr, NULL, 0, xbar->dma_requests,
- GFP_KERNEL);
+ mutex_lock(&xbar->mutex);
+ map->xbar_out = find_first_zero_bit(xbar->dma_inuse,
+ xbar->dma_requests);
+ mutex_unlock(&xbar->mutex);
+ if (map->xbar_out == xbar->dma_requests) {
+ dev_err(&pdev->dev, "Run out of free DMA requests\n");
+ kfree(map);
+ return ERR_PTR(-ENOMEM);
+ }
+ set_bit(map->xbar_out, xbar->dma_inuse);
+
map->xbar_in = (u16)dma_spec->args[0];
dma_spec->args[0] = map->xbar_out + xbar->dma_offset;
@@ -303,8 +314,6 @@ static int ti_dra7_xbar_probe(struct platform_device *pdev)
if (!xbar)
return -ENOMEM;
- idr_init(&xbar->map_idr);
-
dma_node = of_parse_phandle(node, "dma-masters", 0);
if (!dma_node) {
dev_err(&pdev->dev, "Can't get DMA master node\n");
@@ -326,6 +335,12 @@ static int ti_dra7_xbar_probe(struct platform_device *pdev)
}
of_node_put(dma_node);
+ xbar->dma_inuse = devm_kcalloc(&pdev->dev,
+ BITS_TO_LONGS(xbar->dma_requests),
+ sizeof(unsigned long), GFP_KERNEL);
+ if (!xbar->dma_inuse)
+ return -ENOMEM;
+
if (of_property_read_u32(node, "dma-requests", &xbar->xbar_requests)) {
dev_info(&pdev->dev,
"Missing XBAR input information, using %u.\n",
@@ -347,6 +362,7 @@ static int ti_dra7_xbar_probe(struct platform_device *pdev)
xbar->dmarouter.route_free = ti_dra7_xbar_free;
xbar->dma_offset = (u32)match->data;
+ mutex_init(&xbar->mutex);
platform_set_drvdata(pdev, xbar);
/* Reset the crossbar */